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Transportation Project Services Division

Project Delivery

To view Cobb DOT's current bids and requests for proposals, please visit the Bids/RFPs page.

For more information on Cobb DOT policies, design details, and permitting, please visit the Policies/Permitting page.

For information on current projects, please visit the Project Updates page.

The project delivery process and the phases required vary from project to project depending on the size, level of complexity, and funding sources. 

In general, this process involves planning, concept development, engineering, land acquisition, and construction services.

While in-house design services are provided for some projects, Cobb DOT contracts with consultants for engineering and construction services for other projects using the “Policy for Procurement of Professional Services.” 

Consultants are selected to provide engineering services using either the request for proposals (RFP) method or task order on-call contracting. 

In the RFP method, Cobb DOT issues a request for proposers to provide detailed information regarding the firm’s staffing, experience and performance on similar projects, approach to the scope of work, availability, and financial stability. Firms are evaluated by a selection committee that makes a recommendation for award.

For task order on-call contracting, Cobb DOT selects from a pool of firms that are pre-qualified on a biennial basis to provide services in specific categories. Firms pre-qualified in a specific service category are evaluated by a selection committee that makes a recommendation for award.

Firms are selected to provide construction services for Cobb DOT using the Bid/Build method, which is similar to the RFP process. During Bid/Build, contractors provide bids, which are evaluated by a selection committee that makes a recommendation for award. 
Regardless of the procurement method used, Cobb DOT presents the selected firm to the Board of Commissioners (BOC) for approval prior to issuing notice to proceed.

Project Identification/Prioritization

While Cobb County’s CTP assists with identifying short- and long-term transportation priorities, the process for identifying and prioritizing projects varies based upon the project type and how the project is funded. 

The following is a brief description of processes and considerations used by Cobb DOT in identifying some of the most common types of projects for implementation. 
Safety and Operational Improvements: High crash locations are evaluated by staff using AASHTO Highway Safety Manual and ranked based on public safety and benefit/cost ratios.

  • Sidewalks: Projects are identified based on gaps in the current system, expressed need from citizens, and District Commissioner recommendations.
  • Bridges/Culverts: Locations are identified based on GDOT inspections and sufficiency ratings (for culverts/bridges spanning more than 20 feet) and Cobb DOT structural inspections (for culverts bridges spanning less than 20 feet).
  • Resurfacing: Cobb DOT prioritizes resurfacing activities based on the condition of the roadway surface. Roads are inspected and assigned an overall condition index (OCI) rating based on the observed type and severity of surface issues, such as cracking, potholes, rutting, roughness and oxidation. Roadways with a poor OCI rating are prioritized for resurfacing. Utility work/relocations and projects planned by Cobb DOT, Cobb County Water System, Cobb County-Marietta Water Authority, and other local or regional entities are taken into account when evaluating locations as well.
  • Drainage System: Projects are prioritized to address locations where drainage facilities under and adjacent to the roadways have deteriorated to the point where they no longer function as intended.  

Concept Development 

The goal of the concept development phase is to identify a solution that is cost-effective and has the least impact to the community and environment.

The concept development phase of the project delivery process includes drafting a well-defined and well-justified need and purpose statement focusing on the primary transportation need to be addressed.  Elements of the project addressed during this phase include, but are not limited to, data collection, coordination with local stakeholders, development of a reasonable number of sensible and practical conceptual alternatives and investigation of all aspects of a project. These aspects may include environmental, right-of-way, access, utilities, design, community involvement, and construction feasibility.

Projects require varying levels of public involvement, depending on the scope, funding source, and potential impacts of the project. If a Public Information Open House is planned, it is usually conducted during this phase of the project delivery process. In general, public involvement at this stage involves soliciting input on a proposed project concept and addressing public concerns and questions. Involving the public at this stage is essential in having the flexibility to address public concerns before development of full engineering plans.


The engineering phase includes the development of preliminary plans, final plans and construction costs for the selected alternative as well as obtaining environmental permits. 

Preliminary plans advance conceptual plans by adding details such as width and depth transitions, curbs, guard rails, cut-to-fill transitions, drives, intersecting highway approaches, drainage and erosion control, traffic signs, pavement markings, street lighting, signalization, and detours. Cross sections are established, construction limits and notes are placed on the layouts, and quantities are computed for all anticipated construction items.  

Most permit applications are prepared during or soon after preliminary design plans are completed and approved.

Final plan design includes the development of most of the structural design, traffic signal, and landscaping details; acquisition of land and/or rights; development and execution of utility or railroad agreements; and preparation of special provisions. Final design culminates in the completion of the contract plans, specifications and estimate and the advertisement of the project for receipt of bids.

Land Acquisition

While not needed for every project, acquisition of land from private property owners sometimes becomes necessary. In these cases, the value of the property is determined by an independent contractor (not a County employee) that is certified by the State of Georgia and selected from a pre-qualified list of independent fee-based real estate appraisers. 

The value is determined based on the appraiser’s inspection of the property, taking into consideration its physical characteristics, easements and all other elements that affect its value. Recent sales of like properties in the area also are reviewed. From the inspection and comparison with recent sales, the value of the property is determined. This value is used as the basis for the county to begin negotiations with the property owner.


The construction phase includes construction of the final design. The contractor’s sequence of construction, type of equipment used, and methods of construction vary depending on the type of project being constructed. 

Cobb DOT works with property owners and meets with local businesses and contractors throughout construction process. Updates on construction progress are posted online at Separate websites, project newsletters and brochures are sometimes developed for larger projects.

Once construction is substantially complete, a final inspection of the project occurs, punch list items are addressed, and post construction monitoring begins. 

Project Funding

While the county may use general funds for projects, the majority of projects completed by Cobb DOT are funded by the county’s Special Purpose Local Option Sales Tax (SPLOST) program or a combination of SPLOST and other local, state, federal funding. 

Cobb DOT also receives formula grant funding from the Georgia Department of Transportation, Federal Transit Association and Federal Highway Administration.

Cobb County’s SPLOST

The SPLOST has been a fixture in Cobb County for decades, helping the county and its cities upgrade its infrastructure without putting more burden on property taxes.
In November 2020, the Cobb County voters approved a the continuation of a six-year one-cent SPLOST, which takes effect on January 1, 2022.

A large portion of the 2022 SPLOST revenue will go toward Cobb DOT projects, especially road resurfacing.  The 2022 SPLOST project list also contains multiple public safety projects, a new animal shelter, parks and library safety enhancements, and funding for projects in Cobb’s six cities. SPLOST is a crucial part of the infrastructure improvement process for the cities within Cobb County.

SPLOST Oversight 

A group of 15 citizens, the SPLOST Citizens Oversight Committee, represents the interests of the residents of Cobb County by assuring that the County is accountable for funds generated by the one-percent SPLOST program and that it is implemented in an expedient, organized, and accountable manner.

What is a SPLOST? 

Georgia law allows local jurisdictions to use sales tax proceeds as funding for capital improvement projects that would otherwise be paid for with general fund and property tax revenues. Governments cannot use SPLOST funds to pay for operating expenses such as personnel salaries or ongoing expenses. 

This sales tax revenue is authorized by Georgia law as a Special Purpose Local Option Sales Tax (SPLOST). A SPLOST is enacted upon the approval of a local referendum by Cobb County voters.